Humans. The effects of PCBs have been studied in humans who were exposed through diet, work, and industrial accidents. PCBs are reasonably anticipated to be human carcinogen (NTP 2002). They are associated with skin, liver, biliary tract, and intestinal cancers. Other effects of PCBs include respiratory effects, gastrointestinal damage (nausea, vomiting, abdominal pain), eye irritation, increased susceptibility to infection, and hypothyroidism (ATSDR 2000b, Persky, et al. 2001). Other possible health effects associated with PCB exposure are menstrual irregularities and decreased fertility in women. Inconsistent associations have been noted with non-Hodgkin's lymphoma, breast cancer, cardiovascular disease, sperm and fertility in males, low birth weight and head circumference (ATSDR 2000b). PCB exposure in the womb or during lactation is also associated with decreased IQ and impaired psychomotor development, decreased immune function, altered liver enzyme and lipid levels, and skin disease (chloracne) (ATSDR 2000b).

PCB-62

Polychlorinated biphenyls, or PCBs, are toxic, persistent, bioaccumulative, and lipophilic ("fat-loving"). This means that PCBs build up and are stored in fatty tissues and fluids, such as breast milk, and can be passed on to fetuses and infants during pregnancy and lactation. In humans PCBs are linked to increased rates of a number of cancers, including malignant melanoma; non-Hodgkin's lymphoma; and brain, liver, and lung cancer. PCB poisonings in humans have caused fetal and infant death, birth defects, and brain damage in children exposed in the womb. PCBs are known to interfere with hormonal processes. In 1976, the manufacture of PCBs was banned in the United States because of concern for human health impacts, but are still widely found in the general population of the U.S.

In humans, PCBs are associated with skin lesions, thyroid disruption, and altered menstrual cycling, as well as damage to the nervous, immune, and cardiovascular systems. PCB exposure in the womb or during lactation is also associated with decreased IQ and impaired psychomotor development, decreased immune function and skin disease (chloracne) (ATSDR 2000b). The National Toxicology Program considers several PCB mixtures to be "reasonably anticipated" human carcinogens (NTP 2002). Likewise, EPA considers PCBs to be "probable" human carcinogens (EPA 2002b).

In laboratory animals, PCBs are known to cause cancer and damage to the reproductive, endocrine, immune, and nervous systems. In addition, PCBs damage the kidney and gastrointestinal tract, and cause birth defects.

PCB-62 has been found in 22 of the 26 people tested in EWG/Commonweal studies.